Needle apparatus for closing septal defects and methods for using such apparatus

ABSTRACT

Apparatus and methods for closing a septal defect including a flap of tissue partially detached from a septum of a heart. A needle is advanced through a patient&#39;s vasculature within a delivery apparatus until the needle is disposed within a first chamber adjacent the septum. The needle is directed through the flap of tissue until the needle is disposed within a second chamber opposite the septum. A filament attached to an intermediate region of the needle is pulled, thereby causing the needle to pivot about the intermediate region such that the ends of the needle straddle the septal opening. A locking element is secured to the filament to secure the flap of tissue against the septum, and the filament is cut. Alternatively, the filament is biased to coil to engage the flap of tissue and secure the needle against the septum to close the opening.

FIELD OF THE INVENTION

[0001] The present invention relates generally to apparatus and methodsfor treating septal defects, and more particularly to apparatus andmethods for closing a patent foramen ovale or other septal defect thatinclude a flap of tissue using a needle device.

BACKGROUND

[0002] During development of a fetus in utero, blood is generallyoxygenated by the mother's placenta, not the fetus' developing lungs.Most of the fetus' circulation is shunted away from the lungs throughspecialized vessels or foramens that are open during fetal life, butgenerally close shortly after birth. Occasionally, however, theseforamen fail to close and create hemodynamic problems, which mayultimately prove fatal unless treated.

[0003] One defect that may occur is a patent foramen ovale (“PFO”) orpatent ductus arteriosus (“PDA”), which may occur between the left andright atria of the heart. During fetal life, an opening called theforamen ovale allows blood to pass directly from the right atrium to theleft atrium (bypassing the lungs). Thus, oxygenated blood from theplacenta may travel through the vena cava into the right atrium, throughthe foramen ovale into the left atrium, and from there into the leftventricle for delivery via the aorta to the fetus' body. After birth,the foramen ovale is replaced with a membrane called the fossa ovalis,and over time, a solid mass of tissue may form.

[0004] Occasionally, this membrane and tissue mass fail to form orcompletely close the foramen ovale, which may be fatal if untreated.Similar defects may occur in other regions within a septum betweenchambers of the heart, such as atrial septal defects, ventricular septaldefects, and the like.

[0005] To close such defects, open surgery may be performed to ligateand close the defect. Such procedures are obviously highly invasive andpose substantial morbidity and mortality risks.

[0006] Alternatively, catheter-based procedures have been suggested.These may involve introducing umbrella-like structures into the heartthat include opposing expandable structures connected by a hub. One ofthe expandable structures is inserted through the defect, and both areexpanded to secure the tissue surrounding the defect between thestructures in an attempt to seal and close the defect. Such structures,however, involve frame structures that support membranes, both of whichmay fail during the life of the patient being treated, opening thedefect, and/or releasing segments of the structure within the patient'sheart.

[0007] Accordingly, apparatus and methods for closing patent foramenovale, patent ductus arteriosus, or other septal defects would beconsidered useful.

SUMMARY OF THE INVENTION

[0008] The present invention is directed to apparatus and methods forclosing patent foramen ovale (“PFO”), patent ductus arteriosus (“PDA”),or other septal defects.

[0009] In accordance with a first aspect of the present invention, anapparatus for closing a septal defect is provided that includes anelongate needle including a first end defining a tissue-penetrating tip,and a second end defining a substantially blunt tip. A filament extendsfrom an intermediate portion of the needle between the first and secondends, and a locking element, such as a clip, clamp, cross-brace, and thelike, may be securable to the filament, thereby preventing the lockingelement from moving along the filament away from the needle.

[0010] Preferably, the needle has a tapered cross-section such that thesecond end is substantially larger than the first end. A slot may beprovided in the needle that extends from the intermediate portion to thesecond end, the slot having a size for receiving a portion of thefilament therein. The second end of the needle may include a flaredouter edge and/or a rounded inner edge.

[0011] In one embodiment, the locking element may be a clip that isslidable along the filament towards the needle, the clip includingopposing arms having teeth or other engaging elements for preventing theclip from being moved along the filament away from the needle.Alternatively, the clip may be plastically deformable such that the clipmay received around the filament and then crimped or otherwise securedto the filament during closure of a septal defect, as explained furtherbelow.

[0012] In accordance with another aspect of the present invention, adelivery apparatus for delivering a needle apparatus, such as thatdescribed above, is provided that includes an outer catheter and apusher member that are slidably coupled to one another. The catheter maybe a tubular member including proximal and distal ends and a lumentherebetween, the distal end having a size for insertion into a bloodvessel or other body lumen. The needle may be carried within the lumensuch that the first end is disposed distally to the second end.

[0013] The pusher member may be an inner catheter or other elongatemember that is disposed within the lumen of the outer catheter. Thepusher member may include a distal end that may be disposed proximatethe second end of the needle, the pusher member being movable axiallyrelative to the tubular member for ejecting the needle distally from thelumen. The pusher member may include a lumen extending proximally fromthe distal end of the pusher member such that the filament extendingfrom the needle may be received through the lumen.

[0014] An actuator may be provided on the proximal end of the tubularmember and/or the pusher member for advancing the pusher member relativeto the tubular member. Preferably, the actuator may limit advancement ofthe pusher member such that the distal end of the pusher member extendsonly a predetermined distance beyond the distal end of the tubularmember when activated. The actuator may also be coupled to the filamentreceived through the lumen in the pusher member for applying proximaltension to the filament during use, as described further below.

[0015] The lumen of the catheter may include an enlarged distal regionproximate the distal end for receiving the needle therein. For example,the second end of the needle may have a cross-section that issubstantially larger than a cross-section of the distal end of thepusher member. In addition, the second end of the needle may have aflared outer edge such that the second end extends laterally from thedistal end of the pusher member. Alternatively, the second end of theneedle may simply be larger in cross-section than the distal end of thepusher member, In addition, the second end of the needle may include arounded edge for facilitating pivoting of the needle about theintermediate region when the filament is pulled proximally.

[0016] In addition, the delivery apparatus may include a clip carrierhaving a proximal end and a distal end having a size for introductioninto a body lumen. A clip or other locking element may be releasablycarried by the distal end of the clip carrier, the clip includingopposing arms defining a slot therebetween for receiving a filamenttherein. The clip carrier may include a hammer/anvil arrangement forplastically deforming at least one of the opposing arms to engage afilament received within the slot. The clip carrier may be completelyseparate from the catheter and pusher member or may be carried by thecatheter and/or pusher member. For example, the catheter may include anadditional lumen through which the clip carrier may be advanced.

[0017] In a further alternative, the delivery apparatus may include animaging device including an imaging element associated with the distalend of the tubular member for imaging beyond the distal end of thetubular member. For example, the imaging device may be an endoscope orultrasound device that may be received within a lumen of the tubularmember or may be a separate device that may introduced independentlyinto the patient but used in conjunction with the delivery apparatusduring a procedure.

[0018] In accordance with yet another aspect of the present invention, amethod is provided for closing a PFO or other septal defect within apatient's heart. Generally, the septal defect includes a flap of tissuepartially detached from a septum wall between first and second chambersof the heart, the flap of tissue and surrounding tissue of the septumwall defining a septal opening through the septum wall. Initially, aneedle may be provided that includes a first end defining atissue-penetrating tip, a second end defining a substantially blunt tip,and an intermediate portion between the first and second ends from whicha filament extends.

[0019] The needle may be advanced through the patient's vasculatureuntil the needle is disposed within the first chamber of the heartadjacent the septal opening. For example, the needle may be disposedwithin a distal end of a delivery apparatus including a catheter and apusher member slidably coupled to one another. The distal end of thedelivery apparatus may be advanced through the patient's vasculature,e.g., from a percutaneous entry site, into the first chamber until thedistal end is disposed adjacent the flap of tissue.

[0020] The first end of the needle may be directed through the flap oftissue until the second end passes through the flap of tissue and theneedle is disposed within the second chamber of the heart. For example,the pusher member may be advanced distally relative to the catheter,thereby directing the needle from within the delivery apparatus and intoand through the flap of tissue. Preferably, the pusher member isadvanced a predetermined distance, e.g., such that the distal end of thepusher member extends completely through the flap of tissue to ensurethat the needle is directed entirely into the second chamber.

[0021] The filament may then be pulled proximally, thereby causing theneedle to pivot about the intermediate region such that the first andsecond ends of the needle straddle the septal opening within the secondchamber. As the filament is pulled, the blunt tip of the needle mayengage a distal surface of the flap of tissue, thereby preventing theneedle from being pulled back through the flap of tissue. The blunt tipof the needle may include an enlarged or flared end, e.g., larger thanthe distal end of the pusher member, also to prevent the needle frombeing pulled through the flap of tissue. Instead, the blunt tip of theneedle may slide along a distal surface of the flap of tissue and/or theseptum wall, thereby causing the needle to pivot about the intermediateregion of the needle. Preferably, the blunt tip of the needle includes arounded inner edge for facilitating movement of the needle along thedistal surface.

[0022] The flap of tissue may be directed into engagement with theseptum wall to at least partially close the septal opening. For example,a locking element may be secured to the filament, the locking elementengaging the proximal surface of the flap of tissue to secure the flapof tissue between the needle and the locking element. To accomplishthis, a clip carrier may be introduced into the first chamber of theheart. The clip carrier may be manipulated to receive the filamentwithin a clip carried by the clip carrier, and then the clip may becrimped or otherwise plastically deformed, e.g., by a mechanical crimperon the clip carrier, to secure the clip to the filament. Alternatively,a locking element may be slidably secured on the filament. The lockingelement may be slid along the filament towards the needle until the flapof tissue is secured against the tissue surrounding the septal opening.The locking element may include teeth or other elements that accommodatesliding the locking element along the filament towards the needle, butprevent subsequent movement of the locking element along the filamentaway from the needle. In addition, the needle and/or locking element mayhave lengths greater than a width of the septal opening, such that theflap of tissue may be secured between the needle and the lockingelement, thereby substantially closing the septal opening. The filamentmay be cut or otherwise detached from the delivery apparatus, and thedelivery apparatus removed from the patient's body.

[0023] In accordance with still another aspect of the present invention,an apparatus is provided that includes an elongate needle including afirst end defining a tissue-penetrating tip, a second end defining asubstantially blunt tip, and a longitudinal axis extending between thefirst and second ends. A filament extends from an intermediate portionof the needle between the first and second ends. At least a segment ofthe filament may be biased towards a configuration defining a planeextending generally parallel to the longitudinal axis. Thus, thefilament may be extendable towards a generally linear configuration, butmay resiliently attempt to return towards the planar configuration.

[0024] In a preferred embodiment, the filament includes first and secondsegments. The first segment may be attached to the intermediate portionof the needle and biased to extend transversely with respect to thelongitudinal axis. The second segment extends from the first segment andmay be biased to extend transversely to the first segment such that thesecond segment defines the plane that extends generally parallel to thelongitudinal axis of the needle. The second segment may be biasedtowards a coiled configuration, the coiled configuration lyingsubstantially within the plane. Alternatively, the second segment may bebiased towards other planar configurations lying substantially withinthe plane, for example, including at least one of an “L,” a “U,” a “Y,”and/or an “S” shape.

[0025] The apparatus may include a tubular member, including proximaland distal ends and a lumen extending therebetween. The distal end mayhave a size for insertion into a blood vessel. Generally, the needle iscarried within the lumen such that the first end is disposed distally tothe second end. A pusher member may be slidably disposed within thelumen, the pusher member including a distal end disposed proximate thesecond end of the needle. Preferably, the pusher member is movableaxially relative to the tubular member for ejecting the needle distallyfrom the lumen.

[0026] The pusher member and/or the tubular member may include agripping mechanism for releasably securing a loose end of the filament,thereby restraining the filament in the generally linear configuration.An actuator may also be provided on the proximal end of the pushermember and/or the tubular member for releasing the loose end of thefilament, whereupon the filament may be free to assume the planarconfiguration.

[0027] The apparatus may be used for closing a septal defect within apatient's heart, similar to the embodiment described above. The needlemay be advanced through the patient's vasculature, e.g., within thetubular member, until the needle is disposed within the first chamber ofthe heart adjacent the septal opening. The first end of the needle maybe directed through the flap of tissue until the second end passesthrough the flap of tissue and the needle is disposed within the secondchamber of the heart. The filament may be pulled, thereby causing theneedle to pivot about the intermediate region such that the first andsecond ends of the needle straddle the septal opening within the secondchamber. The filament may then be released, the filament resilientlyassuming a generally planar configuration, thereby engaging the flap oftissue between the needle and the filament to at least partially closethe septal opening.

[0028] Other objects and features of the present invention will becomeapparent from consideration of the following description taken inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0029]FIG. 1 is a perspective view of a first preferred embodiment of aneedle apparatus for closing a septal defect, in accordance with thepresent invention.

[0030]FIG. 2 is a cross-sectional side view of a delivery apparatus fordelivering the needle apparatus of FIG. 1.

[0031]FIG. 3 is a cross-sectional view of a heart including a PFO in aseptum wall of the heart, showing an apparatus being introduced fortreating the PFO.

[0032]FIGS. 4A and 4B are perspective details of the PFO of FIG. 3,showing a method for closing a PFO using the needle apparatus of FIG. 1.

[0033] FIGS. 5A-5D are cross-sectional views, showing a method forclosing a PFO using the needle apparatus of FIG. 1.

[0034]FIG. 6 is a perspective view of a second preferred embodiment of aneedle apparatus for closing a septal defect, in accordance with thepresent invention.

[0035]FIG. 7 is a cross-sectional side view of an apparatus fordelivering the needle apparatus of FIG. 6.

[0036]FIGS. 8A and 8B are cross-sectional views, showing a method forclosing a PFO using the needle apparatus of FIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0037] Turning now to the drawings, FIGS. 1 and 2 show a first preferredembodiment of an apparatus 10 for closing a septal defect, such as a PFOor PDA, in accordance with the present invention. Generally, theapparatus 10 includes a needle apparatus 12 and a delivery apparatus 50for introducing and deploying the needle apparatus 12.

[0038] With particular reference to FIG. 1, the needle apparatus 12includes an elongate needle 14 including a first end 16 defining atissue-penetrating tip, a second end 18 defining a substantially blunttip, and an intermediate region 20 between the first and second ends 16,18. The needle 14 may be formed from a variety of substantially rigidbiocompatible materials, e.g., stainless steel.

[0039] Preferably, the needle 14 includes a longitudinal slot 22 thereinthat extends between the intermediate region 20 and the second end 18.The second end 18 of the needle 14 may include a flared outer edge 24that extends transversely outwardly, and a rounded inner edge 26. Thesecond end 18 of the needle 14 preferably has a cross-section that issubstantially larger than the first end 16, and more preferably that issubstantially larger than the intermediate region 20. For example, thesecond end 18 may have a generally “U” shape, as shown, defining theslot 22 therein.

[0040] The needle apparatus 12 also includes a filament 30 that extendsfrom the intermediate region 20 of the needle 14. The filament 30 ispreferably formed from a substantially inelastic biocompatible material,such as non-bioabsorbable suture material, e.g., plastic. Preferably, afirst end 32 of the filament 30 is substantially permanently attached tothe intermediate region 20, e.g., through a loop 34 on the intermediateregion 20, and a second end (not shown) of the filament 30 is loose.Alternatively, a wall of the intermediate region 20 may include a hole(not shown) through which the first end 32 of the filament 30 may besecured. In a further alternative, the intermediate region 20 mayinclude a recess, groove, slot, and the like (not shown), for receivingthe first end 32, e.g., such that the filament 30 may be tied around theintermediate region 20 and received within the recess. In addition oralternatively, the first end 32 of the filament 30 may be attached tothe needle 14 by an adhesive or other bonding method, sonic welding, andthe like.

[0041] In addition, the needle apparatus 12 may also include a clip orother locking element 40 that may be secured to the filament 30. In apreferred embodiment, the clip 40 includes opposing arms 42 defining aslot 44 therebetween for receiving the filament 30 therein. The innersurfaces of the arms 42 may include teeth or other engaging elements(not shown) that allow the clip 40 to be directed along the filament 30towards the needle 12, but prevent the clip 40 from being moved alongthe filament 30 away from the needle 12. Alternatively, the clip 40 maybe plastically deformable such that the arms 42 may be disposedinitially apart sufficient to freely introduce the filament 30therebetween, and then crimped or otherwise directed towards one anotherto frictionally secure the clip 40 at a desired location on the filament30.

[0042] With particular reference to FIG. 2, the delivery apparatus 50generally includes an outer catheter or tubular member 52, and an innercatheter or pusher member 54. The outer catheter 52 includes a proximalend (not shown), and a distal end 56 having a size for insertion into ablood vessel or other body lumen (not shown). The distal end 56preferably has a tapered and/or rounded distal tip 58, e.g., forfacilitating substantial atraumatic advancement of the deliveryapparatus 50 through a patient's vasculature. The outer catheter 52 alsoincludes a lumen 60 therein that extends between the proximal and distalends 56. In the embodiment shown, the lumen 60 includes an enlargeddistal region 62 having a size for receiving the needle 12. Preferably,the needle 14 may be received in the enlarged distal region 62 such thatthe first end 16 is disposed distally to the second end 18 therein.

[0043] The pusher member 54 includes a proximal end (not shown) and adistal end 64 having a size such that the pusher member 54 may beslidably disposed within the lumen 60 of the outer catheter 52. Thedistal end 64 is preferably substantially blunt and has a cross-sectionthat is substantially smaller than a projected cross-section of theneedle 12. The distal end 64 is disposed proximate the second end 18 ofthe needle 12, and the pusher member 54 is movable axially relative tothe outer catheter 52 for ejecting the needle 12 distally from the lumen60, as described further below. In a preferred embodiment, the pushermember 54 includes a lumen 66 extending proximally from the distal end64 of the pusher member 54, and preferably extending to the proximal endof the pusher member 54 As shown, the lumen 66 has a size for receivingthe filament 30 therethrough.

[0044] Alternatively, the pusher member 54 may include a longitudinalgroove or slot (not shown) extending along an outer wall of the pushermember 54 from the distal end 64 to the proximal end. The groove or slotmay have a size for slidably receiving the filament 309 therein. In afurther alternative, the delivery apparatus may include interlockedrails (not shown) that may slide axially relative to one another in acontrolled manner, instead of the outer catheter 52 and the pushermember 54.

[0045] An actuator, e.g., a handle device (not shown), may be providedon the proximal end of the outer catheter 52 and/or the pusher member 54that may limit relative axial movement of the outer catheter 52, thepusher member 54, and/or the filament 30. For example, the actuator maybe fixed to the outer catheter 52 and coupled to the pusher member 54for advancing the pusher member 54 relative to the outer catheter 52 (oralternatively, for retracting the outer catheter 52 relative to thepusher member 54). Preferably, the actuator allows advancement of thepusher member 54 such that the distal end 64 of the pusher member 54extends a predetermined distance beyond the distal tip 58 of the outercatheter 52 and then prevents further distal advancement. In addition,the actuator may be coupled to the second end of the filament 30, e.g.,for pulling the filament proximally relative to the outer catheter 52and/or pusher member 54, as described further below.

[0046] Use of the apparatus 10 for closing a septal defect 94 is shownin conjunction with FIGS. 3-5D. FIG. 3 generally shows a heart 90 of apatient, including heart chambers 91, 92 separated by a septum wall 93.The septal defect 94, such as a PFO or PDA, is shown in the septum wall93, which may be located in the septum wall between the right atrium andthe left atrium of the heart. As best seen in FIGS. 4A-5D, the septaldefect 94 may include a flap of tissue 95 that is at least partiallydetached from the septum wall 93, thereby defining an opening 96 in theseptum wall 93. Alternatively, the septal defect may be an opening thatextends through the septum wall 93, e.g., laterally such that the septaldefect includes flaps of tissue that partially overlap one another (notshown).

[0047] The apparatus 10, i.e., the delivery apparatus 50 with the needleapparatus 12 therein (the latter not shown in FIG. 3, see FIGS. 5A-5D),may be introduced into the patient's vasculature, e.g., from apercutaneous entry site in a peripheral vessel, such as the femoralartery, carotid artery, and the like (not shown). The apparatus 10 maybe advanced endoluminally within the patient's vasculature, e.g.,through the aortic arch 97 and into the heart 90 until the distal end 56is disposed within the chamber 91, which is shown in FIG. 3 to be theleft atrium. Preferably, access into the heart 90 may be obtained usinga venous approach. The apparatus 10 may be introduced percutaneouslyinto a peripheral vein, such as the femoral or jugular vein, andadvanced through the vena cava (not shown) into the right atrium.

[0048] With particular reference to FIGS. 5A-5D, the distal end 56 ofthe apparatus 10 may be advanced into contact with a proximal surface 95a of the flap of tissue 95, e.g., such that the flap of tissue 95 isdisposed proximate the septal opening 96, as shown in FIG. 5A (e.g.,within the right atrium, not shown). The pusher member 54 may beadvanced distally relative to the outer catheter 52, thereby piercingthe first end 16 of the needle 14 through the flap of tissue 95 untilthe needle 14 enters the chamber 92 beyond the septum wall 93 (e.g., theleft atrium, not shown), thereby creating a puncture 99. Preferably, thepenetrating tip on the first end 16 of the needle 14 is substantiallysharp to facilitate piercing and passing through the flap of tissue 95.The substantially blunt tip on the second end 18 of the needle 14enhances engagement with the distal end 64 of the pusher member 54 tofacilitate pushing the needle 14 through the flap of tissue 95 to createthe puncture 99.

[0049] Preferably, the pusher member 54 is advanced distally until thesecond end 18 of the needle 14 passes entirely through the flap oftissue 95, as shown in FIG. 5B. For example, the actuator (not shown) onthe delivery apparatus 50 may allow controlled advancement of the pushermember 54 to allow the distal end 64 of pusher member 54 to be disposeda predetermined distance beyond the distal tip 58 of the outer catheter52. Preferably, the predetermined distance is a distance greater than athickness of the flap of tissue 95, e.g., at least about two to tenmillimeters (2-10 mm), such that the distal end 64 of the pusher member54 passes through the puncture 99, thereby ensuring that the second end18 of the needle 14 is advanced completely beyond the distal surface 95b of the flap of tissue 95.

[0050] The pusher member 54 may then be retracted proximally, e.g., towithdraw the distal end 58 back through the flap of tissue 95 and atleast partially into the lumen 60 of the outer catheter 52. The filament30 may be pulled proximally, either before or after retraction of thepusher member 54, thereby causing the second end 18 of the needle 14 toengage the distal surface 95 b of the flap of tissue 95. Because of thesubstantially blunt tip on the second end 18, the needle 14 may not passback through the puncture. Preferably, because of the flared outer edge24, the second end 18 of the needle 14 is offset laterally relative tothe distal end 64 of the pusher member 54, thereby preventing the secondend 18 from following the pusher member 54 back through the puncture 99.Thus, the second end 18 engages the distal surface 95 b and retains theneedle 14 entirely within the chamber 92.

[0051] With particular reference to FIG. 5C, because the filament 30 iscoupled to the intermediate region 20 of the needle 14, continuedpulling of the filament 30 proximally may cause the needle 14 to pivotabout the intermediate region 20. Preferably, the rounded inner edge 26allows the second end 18 of the needle 14 to slide and pivot along thedistal surface 95 b of the flap of tissue 95 and/or along the septumwall 93. As the filament 30 is pulled further, the needle 14 is directlysubstantially transversely, and preferably substantially parallel to theseptum wall 93, e.g., until it abuts the distal surface 95 b of the flapof tissue 95 and/or the septum wall 93, as best seen in FIGS. 4A and 5C.Preferably, a length of the needle 14 is substantially longer than awidth of the opening 96 such that the first and second ends 16, 18 ofthe needle 14 straddle the opening 96 and engage the septum wall 93 oneither side of the septal defect 94.

[0052] As best seen in FIGS. 4B and 5D, the clip 40 may then be securedto the filament 30 such that the clip 40 substantially abuts theproximal surface 95 a of the flap of tissue 95. For example, in oneembodiment, the clip 40 may be provided within the lumen of the outercatheter 54 and advanced along the filament 30 towards the needle 14until the clip 54 contacts the proximal surface 95 a. As the clip 40 isdirected further distally, the flap of tissue 95 is forced into contactwith the septum wall 93 surrounding the opening 96, possible evenfilling the opening 96, as shown in FIG. 4B.

[0053] Alternatively, the clip 40 may be carried by a separate device(not shown) than the delivery apparatus 50. For example, a clip carrier(not shown) may be introduced into the chamber 91, e.g., from apercutaneous entry site (not shown), and advanced endoluminally into thechamber 92. In a further alternative, the outer catheter 52 of thedelivery apparatus 50 may include an additional lumen (not shown) fromwhich a clip carrier may be advanced.

[0054] The clip 40 may be directed around the filament 30 and securedwithin the slot of the filament 30. For example, the clip carrier mayinclude a hammer-anvil arrangement (not shown) that may be used to crimpor otherwise plastically deform the clip 40 to substantially engage thefilament 30. Preferably, tension is applied to the filament 30, and theclip 40 is brought into close proximity with the proximal surface 95 aof the flap of tissue 95 before the clip 40 is crimped, thereby securingthe clip 40 against the flap of tissue 95.

[0055] Alternatively, the clip 40 may be slidably received on thefilament 30, e.g., by a separate clip carrier (not shown) or may beprovided on the filament 30 within the delivery apparatus 50 (also notshown). One or more tools may be used to apply proximal tension to thefilament 30 and drive the clip 40 distally towards the needle 14, e.g.,until the clip 40 engages the flap of tissue 95.

[0056] This arrangement of needle apparatus 12 may be used for a flap oftissue 95 that falls proximally away from the opening 96 in the septumwall 93 (into the proximal chamber 91 shown in FIG. 3). As the clip 40is advanced distally over the filament 30, the first and second ends 16,18 of the needle 14 may provide anchors such that the clip 40 may pushthe flap of tissue 95 into the opening 96 and/or into contact with thesurrounding septum wall 93.

[0057] Alternatively, if the flap of tissue 95 falls distally away fromthe opening 96 (not shown), the filament 30 may be pulled proximally inorder to cause the needle 14 to direct the flap of tissue 95 intocontact with the septum wall 93 surrounding the opening 96 and/or tosubstantially fill the opening 96. To hold the flap of tissue 95 in thisclosed position, a clip (not shown) may be advanced over the filament 30or otherwise secured to the filament 30. Preferably, the clip has alength or cross-section that is greater than the cross-section of theopening 96 such that the clip abuts the septum wall 93 surrounding theopening 96. Thus, the flap of tissue 95 may be sandwiched between theneedle 14 and the clip, which engage opposing surfaces of thesurrounding septum wall in order to secure the flap of tissue 95substantially closed.

[0058] Once the needle 14, clip 40, and flap of tissue 95 are secured asdesired, the filament 30 may be cut and the delivery apparatus 50removed from the patient's body. For example, the clip carrier mayinclude a cutting element (not shown) that may be used to cut thefilament at a location close to the clip 40, as shown in FIGS. 4B and5D. The cutting element may simply be a blade, scissors, and the likethat is deployable from the clip carrier. Alternatively, a cuttingelement may be advanced through a lumen (not shown) in the outercatheter 52, or may be a separate device that may be introducedindependently through the patient's vasculature into the chamber 92 ofthe heart 90.

[0059] It will be appreciate by those skilled in the art that theprocedure described herein may be monitored in a variety of ways. Forexample, the delivery apparatus 50 may include an imaging device, suchas an endoscope or other fiber optic device, an intravascular ultrasound(“IVUS”) device, and the like (not shown). The device may be provided onthe distal end 56 of the outer catheter 52, e.g., attached to oradjacent the distal tip 58 or advanceable from a lumen (not shown)therein. In a further alternative, external imaging may be used, eitheralone or in conjunction with direct visualization. For example, theneedle 14, the clip 40, the outer catheter 52, and/or the pusher member54 may include radiopaque markers (not shown) at predetermined locationsthat may be observed using fluoroscopy and the like.

[0060] Turning to FIGS. 6 and 7, another preferred embodiment of anapparatus 110 is shown for closing a septal defect, such as a PFO orPDA, that generally includes a needle apparatus 112 and a deliveryapparatus 150 for introducing and deploying the needle apparatus 112.

[0061] With particular reference to FIG. 6, the needle apparatus 112includes an elongate needle 114 including a first end 116 defining atissue-penetrating tip, a second end 118 defining a substantially bluntor rounded tip, and a longitudinal axis 119 between the first and secondends 116, 118. The needle 114 may be formed from a variety ofsubstantially rigid biocompatible materials, e.g., stainless steel.

[0062] Preferably, the needle 114 includes a longitudinal slot 122therein that extends between an intermediate region 120 of the needle114 and the second end 118. The second end 118 of the needle 114 mayinclude a flared outer edge and/or a rounded inner edge (not shown),similar to the previous embodiment. The second end 118 of the needle 114preferably has a cross-section that is substantially larger than thefirst end 116, and more preferably that is substantially larger than theintermediate region 120. For example, the second end 118 may have agenerally “U” shape, as shown, defining the slot 122 between edges 123.

[0063] The needle apparatus 112 also includes a filament 130 thatextends from the intermediate region 120 of the needle 114. The filament130 may be formed from a superelastic and/or shape memory material, suchas Nitinol. Preferably, the filament 130 is biased towards a coiledconfiguration, such as that shown in FIG. 6, yet may be deformed into agenerally linear configuration, such as that shown in FIG. 7. A firstend 132 of the filament 130 is substantially permanently attached to theintermediate region 120, e.g., by bonding or welding, similar to theprevious embodiment. Preferably, the first end 132 is attached within oradjacent to the slot 122, and a second end 133 of the filament 130 isloose.

[0064] In its unstressed or relaxed state, the filament 130 includes afirst segment 134 that extends from the first end 132 transversely, andpreferably substantially perpendicularly, to the longitudinal axis 119.The filament 130 also includes a second segment 136 that extendstransversely from the first segment 134, and preferably substantiallyperpendicularly to the first segment 134. More preferably, the secondsegment 136 is biased to define a planar configuration, e.g., in theshape of a coil, as shown in FIG. 6. The planar configuration generallydefines a plane that extends substantially parallel to the longitudinalaxis 119 of the needle 114.

[0065] Alternatively, the second segment 136 may be biased towards otherconfigurations instead of a coil that generally define a plane. Forexample, at least a portion of the second segment 136 may be biasedtowards a generally “L,” “U,” “Y,” and/or “S” shape lying within theplane.

[0066] Turning to FIG. 7, the delivery apparatus 150 generally includesa sheath or outer member 152, and an inner pusher member 154. The sheath152 generally is an elongate tubular member including a proximal end(not shown), a distal end 156, and a lumen 158 extending therebetween.The distal end 156 preferably has a size and shape for facilitatinginsertion into and along a blood vessel or other body lumen (not shown).The lumen 158 has a size for receiving the needle 114 therein,preferably such that the first end 116 is disposed distally to thesecond end 118, as shown.

[0067] The pusher member 154 is slidably disposed within the lumen 158,and includes a distal end 160 that is disposed proximate the second end118 of the needle 114. The pusher member 154 may be movable axiallyrelative to the sheath 152 for ejecting the needle 114 distally from thelumen 158. The pusher member 154 includes a gripping mechanism (notshown) for releasably securing the loose end (also not shown in FIG. 7)of the filament 130. The gripping mechanism may retrain the filament 130in the generally linear configuration, as shown in FIG. 7. The grippingmechanism may include a clamp (not shown) that may be slidably receivedin or otherwise coupled to the pusher member 154. The clamp may beopened to receive the loose end of the filament, closed to secure thefilament thereto, and then opened again to release the filament, asexplained further below. Alternatively, the filament may be directedinto a slot (not shown) in the pusher member and secured within the slotby a coaxial member (also not shown) disposed within or around thepusher member 154.

[0068] An actuator (not shown) may be provided on the proximal end ofthe pusher member 154 and/or the sheath 152 for controlling oractivating movement of the pusher member 154 relative to the sheath 152.In addition or alternatively, the actuator may be activated forreleasing the loose end of the filament 130.

[0069] In addition, an imaging element, such as an IVUS (not shown), maybe associated with the distal end 156 of the tubular member 152 forimaging beyond the distal end 156 of the tubular member 152 during aprocedure, similar to the previous embodiment.

[0070] Turning to FIGS. 8A and 8B, the apparatus 110 may be used toclose and/or seal a septal defect 94 within a patient's heart (notshown). Generally, the septal defect 94 includes a flap of tissue 95partially detached from a septum wall 93 between first and secondchambers of the heart, such as a PFO or PDA as described above, suchthat the flap of tissue 95 and surrounding tissue define a septalopening 96 through the septum wall 93.

[0071] Initially, a needle 114 may be provided that includes a first end116 defining a tissue-penetrating tip, a second end 118 defining asubstantially blunt tip, and an intermediate portion 120 between thefirst and second ends 116, 118 from which a filament 130 extends. Theneedle 114 may be disposed within a lumen 158 or otherwise carried by asheath 152. Preferably, the filament 130 is secured to a pusher member154, the distal end 160 of which is disposed adjacent the second end 118of the needle 114.

[0072] The needle 114, e.g., within the sheath 152, may be advancedthrough the patient's vasculature until the needle 114 is disposedwithin the first chamber of the heart, e.g., adjacent the septal opening96. The first end 116 of the needle 114 may be inserted through the flapof tissue 95, as shown in FIG. 8A, until the second end 118 passesthrough the flap of tissue 95 and an overlapping portion of the septumwall 93. Preferably, the pusher member 154 is advanced against thesecond end 118 of the needle, thereby directing the needle 114 entirelythrough the septum wall 93 until the needle 114 is disposed within thesecond chamber of the heart.

[0073] The filament 130 may then be pulled proximally, thereby causingthe needle 114 to pivot about the intermediate region 120 such that theneedle 114 extends substantially parallel to the septum wall 93. Thefirst and second ends 116, 118 of the needle 114 may straddle the septalopening 95 within the second chamber, similar to the previousembodiment, or otherwise draw the flap of tissue 95 against the septumwall 93. The filament 130 may then be released from the pusher member154, and the sheath 152 and pusher member 152 removed from the patient.

[0074] Once the second end of the filament 114 is released, because ofits inherent bias, the filament 130 may resiliently assume a generallyplanar configuration, thereby engaging the flap of tissue 95 and/or theseptum wall 93 between the needle 114 and the filament 130. Preferably,a first segment 134 of the filament 130 extends transversely from theneedle 114, i.e., through the flap of tissue 95 and septum wall 95. Asecond segment 136 of the filament 130 assumes a planar configurationagainst the flap of tissue 95 to at least partially close the septalopening 95, as shown in FIG. 8B.

[0075] Preferably, as explained above, the filament 130 may assume acoiled configuration defining a plane that is generally parallel withthe septum wall 93. The filament 130 in the coiled configuration mayhave sufficient width to engaging tissue surrounding the opening 96.Alternatively, the filament 130 may simply retain the needle 114 againstthe flap of tissue 95, thereby maintaining the flap of tissue 95 againstthe septum wall 93 to substantially close and/or seal the opening 96.

[0076] While the invention is susceptible to various modifications, andalternative forms, specific examples thereof have been shown in thedrawings and are herein described in detail. It should be understood,however, that the invention is not to be limited to the particular formsor methods disclosed, but to the contrary, the invention is to cover allmodifications, equivalents and alternatives falling within the spiritand scope of the appended claims.

What is claimed is:
 1. An apparatus for closing a septal defect,comprising: an elongate needle comprising a first end defining atissue-penetrating tip, and a second end defining a substantially blunttip; a filament extending from an intermediate portion of the needlebetween the first and second ends; and a locking element securable tothe filament, thereby preventing the locking element from moving alongthe filament away from the needle.
 2. The apparatus of claim 1, whereinthe needle has a tapered cross-section such that the second end issubstantially larger than the first end.
 3. The apparatus of claim 1,wherein the needle comprises a slot therein extending from theintermediate portion to the second end, the slot having a size forreceiving a portion of the filament therein.
 4. The apparatus of claim1, wherein the filament is pivotally coupled to the intermediate portionof the needle.
 5. The apparatus of claim 1, wherein the intermediateportion of the needle comprises a hole through which the filament issubstantially secured to the needle.
 6. The apparatus of claim 1,wherein the locking element comprises a clip slidable along the filamenttowards the needle, the clip comprising engaging elements for preventingthe clip from being moved along the filament away from the needle. 7.The apparatus of claim 1, further comprising: a tubular membercomprising proximal and distal ends and a lumen therebetween, the distalend having a size for insertion into a blood vessel, the needle beingcarried within the lumen such that the first end is disposed distally tothe second end; and a pusher member slidably disposed within the lumen,the pusher member comprising a distal end disposed proximate the secondend of the needle, the pusher member being movable axially relative tothe tubular member for ejecting the needle distally from the lumen. 8.The apparatus of claim 7, wherein the pusher member comprises a lumenextending proximally from the distal end of the pusher member, andwherein the filament is received through the lumen.
 9. The apparatus ofclaim 8, further comprising an actuator on the proximal end of thetubular member for advancing the pusher member relative to the tubularmember such that the distal end of the pusher member extends apredetermined distance beyond the distal end of the tubular member. 10.The apparatus of claim 9, wherein the second end of the needle has across-section that is substantially larger than a cross-section of thedistal end of the pusher member.
 11. The apparatus of claim 10, whereinthe second end of the needle comprises a flared outer edge such that thesecond end extends laterally from the distal end of the pusher member.12. The apparatus of claim 9, wherein the actuator is coupled to thefilament for pulling the filament proximally after the pusher member isadvanced the predetermined distance.
 13. The apparatus of claim 12,wherein the second end of the needle comprises a rounded edge forfacilitating pivoting of the needle about the intermediate region whenthe filament is pulled proximally.
 14. The apparatus of claim 1, furthercomprising a carrier member having a proximal end and a distal endhaving a size for introduction into a body lumen, and wherein thelocking element is releasably carried by the distal end of the carriermember.
 15. The apparatus of claim 14, wherein the locking elementcomprises opposing arms defining a space therebetween for receiving thefilament therein, and wherein the carrier member comprises a hammerarrangement for plastically deforming at least one of the opposing armsto frictionally engage the filament.
 16. The apparatus of claim 1,further comprising an imaging device comprising a imaging elementassociated with the distal end of the tubular member for imaging beyondthe distal end of the tubular member.
 17. The apparatus of claim 16,wherein the imaging device comprises an endoscope received within alumen of the tubular member.
 18. The apparatus of claim 16, wherein theimaging device comprises an elongate member comprising a distal endhaving a size for introduction into a body lumen.
 19. A method forclosing a septal defect within a patient's heart, the septal defectcomprising a flap of tissue partially detached from a septum wallbetween first and second chambers of the heart, the flap of tissue andsurrounding tissue defining a septal opening through the septum wall,the method comprising: providing a needle comprising a first enddefining a tissue-penetrating tip, a second end defining a substantiallyblunt tip, and an intermediate portion between the first and second endsfrom which a filament extends; advancing the needle through thepatient's vasculature until the needle is disposed within the firstchamber of the heart adjacent the septal opening; directing the firstend of the needle through the flap of tissue until the second end passesthrough the flap of tissue and the needle is disposed within the secondchamber of the heart; pulling the filament, thereby causing the needleto pivot about the intermediate region such that the first and secondends of the needle straddle the septal opening within the secondchamber; and directing the flap of tissue into engagement with theseptum wall to at least partially close the septal opening.
 20. Themethod of claim 19, wherein the step of directing the flap of tissuecomprises securing a locking element to the filament, the lockingelement engaging the proximal surface of the flap of tissue to securethe flap of tissue between the needle and the locking element.
 21. Themethod of claim 20, wherein the step of securing the locking elementcomprises introducing a carrier member into the first chamber of theheart, the carrier member carrying the locking element.
 22. The methodof claim 20, wherein the carrier member is manipulated to receive thefilament within a slot in the locking element, and wherein the lockingelement is crimped to secure the filament within the slot.
 23. Themethod of claim 19, wherein a locking element comprises a clip slidablysecured on the filament.
 24. The method of claim 19, wherein the step ofdirecting the flap of tissue comprises advancing the clip along thefilament towards the needle until the flap of tissue is secured againstthe tissue surrounding the septal opening.
 25. The method of claim 19,wherein the step of pulling the filament comprises slidably engaging theblunt tip of the needle along a distal surface of the flap of tissue,thereby causing the needle to pivot about the intermediate region of theneedle.
 26. The method of claim 25, wherein the blunt tip of the needlecomprises a rounded inner edge for facilitating movement of the needlealong the distal surface.
 27. The method of claim 19, wherein the needleis disposed within a distal end of a delivery apparatus comprising acatheter and a pusher member slidably coupled to one another, andwherein the step of advancing the needle comprises advancing the distalend of the delivery apparatus into the first chamber until the distalend is disposed adjacent the flap of tissue.
 28. The method of claim 27,wherein the step of directing the first end of the needle through theflap of tissue comprises advancing the pusher member distally relativeto the catheter, thereby directing the needle from within the deliveryapparatus.
 29. An apparatus for closing a septal defect, comprising: anelongate needle comprising a first end defining a tissue-penetratingtip, a second end defining a substantially blunt tip, and a longitudinalaxis extending between the first and second ends; and a filamentextending from an intermediate portion of the needle between the firstand second ends, at least a segment of the filament being biased towardsa configuration defining a plane extending generally parallel to thelongitudinal axis, the filament being resiliently extendable towards agenerally linear configuration.
 30. The apparatus of claim 29, whereinthe needle has a tapered cross-section such that the second end issubstantially larger than the first end.
 31. The apparatus of claim 29,wherein the needle comprises a slot therein extending from theintermediate portion to the second end, the slot having a size forreceiving a portion of the filament therein.
 32. The apparatus of claim29, wherein the filament comprises first and second segments, the firstsegment attached to the intermediate portion of the needle and biased toextend transversely with respect to the longitudinal axis, the secondsegment extending from the first segment and being biased to extendtransversely to the first segment such that the second segment definesthe plane.
 33. The apparatus of claim 32, wherein the second segment isbiased towards a coiled configuration, the coiled configuration lyingsubstantially within the plane.
 34. The apparatus of claim 32, whereinthe second segment is biased towards a planar configuration lyingsubstantially within the plane.
 35. The apparatus of claim 34, whereinthe planar configuration comprises at least one of an “L,” a “U,” a “Y,”and an “s” shape that lies substantially within the plane.
 36. Theapparatus of claim 29, further comprising: a tubular member comprisingproximal and distal ends and a lumen therebetween, the distal end havinga size for insertion into a blood vessel, the needle being carriedwithin the lumen such that the first end is disposed distally to thesecond end; and a pusher member slidably disposed within the lumen, thepusher member comprising a distal end disposed proximate the second endof the needle, the pusher member being movable axially relative to thetubular member for ejecting the needle distally from the lumen.
 37. Theapparatus of claim 36, wherein the pusher member comprises a grippingmechanism for releasably securing a loose end of the filament, therebyrestraining the filament in the generally linear configuration.
 38. Theapparatus of claim 37, further comprising an actuator on the proximalend of the pusher member for releasing the loose end of the filament,whereupon the filament becomes biased to assume the planarconfiguration.
 39. The apparatus of claim 36, further comprising animaging element associated with the distal end of the tubular member forimaging beyond the distal end of the tubular member.
 40. A method forclosing a septal defect within a patient's heart, the septal defectcomprising a flap of tissue partially detached from a septum wallbetween first and second chambers of the heart, the flap of tissue andsurrounding tissue defining a septal opening through the septum wall,the method comprising: providing a needle comprising a first enddefining a tissue-penetrating tip, a second end defining a substantiallyblunt tip, and an intermediate portion between the first and second endsfrom which a filament extends; advancing the needle through thepatient's vasculature until the needle is disposed within the firstchamber of the heart adjacent the septal opening; directing the firstend of the needle through the flap of tissue until the second end passesthrough the flap of tissue and the needle is disposed within the secondchamber of the heart; pulling the filament, thereby causing the needleto pivot about the intermediate region such that the first and secondends of the needle straddle the septal opening within the secondchamber; and releasing the filament, the filament resiliently assuming agenerally planar configuration, thereby engaging the flap of tissuebetween the needle and the filament to at least partially close theseptal opening.